GRAND RAPIDS — Rebecca Finneran’s peonies are enjoying the unseasonably warm March weather much like anyone else in West Michigan — and that worries her.

Finneran, a horticulture educator with Michigan State University Extension’s Kent County office in Grand Rapids, knows cold weather is threatening to make a comeback in coming weeks, which could kill off West Michigan’s early-blooming flora and crops.

Jeff Andresen, the state climatologist and associate professor of geography at MSU, said the warm spell has kick-started the growing season 2-3 weeks, if not more, ahead of schedule.

Andresen went so far as to say during a Thursday conference call with MSU Extension educators that, weather-wise, Michigan is in “uncharted waters.”

Records show the last similar warm spell in the state happened in 1945, Andresen said. Each time unseasonably warm temperatures arrived in March in the past, he said, they were followed by periods of freezing weather.

“In places like Grand Rapids, the number of freezing temperature events from April through June is more than 10 for those months,” he said. “It’s been as cold in the single digits, Fahrenheit, in early April.”

“We are not out of the woods with regard to cold weather, and the more soft (plant) tissue is exposed, the greater risk that you’re going to lose leaves, chutes, buds, flower buds and fruits if we have a significantly cold pattern,” Finneran said.

“If we see magnolias pushing out and we get a really hard freeze,” she offered as an example, “they’re toast.”

It is possible, Andresen said, that the coming weeks defy history and avoid freezing temperatures altogether.

“But given the past climate and climatology,” he said, “we almost certainly will see colder weather.”